In the field of packaging food and non-food liquid and/or flowable and/or pumpable food and non-food products, a convenient method of packaging such products in thermoplastic film has been developed and is generally known as a form/fill/seal process. In such a process a tube is formed from thermoplastic film, a longitudinal fin or lap seal is made, and an end seal is made by transversely sealing across the tube with heated seal bars to form a conveniently wide heat seal and, consequently, producing a bag or pouch ready to receive a product. After the heat seal is made, the bag or pouch is filled and then another transverse heat seal is made across the width of the tube in a relatively wide band. After cooling, this seal is transversely severed to separate the filled bag from the next bag to be filled. Thus, one wide band seal serves as the bottom seal for one bag and the top seal for another.
Many horizontal and vertical form/fill/seal systems are commercially available from manufacturers or suppliers such as Hayssen, Omori, lapak, and Kartridge Pak.
Vertical form/fill/seal (VFFS) packaging systems have proven to be very useful in packaging a wide variety of food and non-food pumpable and/or flowable products. An example of such systems is the ONPACK™ flowable food packaging system marketed by Cryovac/Sealed Air Corporation. The VFFS process is known to those of skill in the art, and described for example in U.S. Pat. No. 4,506,494 (Shimoyama et al.), U.S. Pat. No. 4,589,247 (Tsuruta et al), U.S. Pat. No. 4,656,818 (Shimoyama et al.), U.S. Pat. No. 4,768,411 (Su), U.S. Pat. No. 4,808,010 (Vogan), and U.S. Pat. No. 5,467,581 (Everette), all incorporated herein by reference in their entirety. Typically in such a process, lay-flat thermoplastic film is advanced over a forming device to form a tube, a longitudinal (vertical) fin or lap seal is made, and a bottom end seal is made by transversely sealing across the tube with heated seal bars. A liquid, flowable, and/or pumpable product, such as a liquid, semiliquid, or paste, with or without particulates therein, is introduced through a central, vertical fill tube to the formed tubular film. Squeeze rollers spaced apart and above the bottom end seal squeeze the filled tube and pinch the walls of the flattened tube together. When a length of tubing of the desired height of the bag has been fed through the squeeze rollers a heat seal is made transversely across the flattened tubing by heat seal bars which clamp and seal the film of the tube therebetween. After the seal bars have been withdrawn the film moves downwardly to be contacted by cooled clamping and severing bars which clamp the film therebetween and are provided with a cutting knife to sever the sealed film at about the midpoint of the seal so that approximately half of the seal will be on the upper part of a tube and the other half on the lower. When the sealing and severing operation is complete, the squeeze rollers are separated to allow a new charge of product to enter the flattened tube after which the aforementioned described process is repeated thus continuously producing vertical form/fill/seal pouches which have a bottom end and top end heat seal closure.
The process can be a two-stage process where the creation of a transverse heat seal occurs at one stage in the process, and then, downstream of the first stage, a separate pair of cooling/clamping means contact the just-formed transverse heat seal to cool and thus strengthen the seal. In some VFFS processes, an upper transverse seal of a first pouch, and the lower transverse seal of a following pouch, are made, and the pouches cut and thereby separated between two portions of the transverse seals, without the need for a separate step to clamp, cool, and cut the seals. A commercial example of an apparatus embodying this more simplified process is the ONPACK™ 2002 VFFS packaging machine marketed by Cryovac/Sealed Air Corporation.
U.S. Pat. No. 4,603,793 (Stern), incorporated herein by reference in its entirety, discloses a coupling means 6a which is mounted on the inside wall of a pouch. Such coupling means, or fitments, offer several advantages in packaging food products, such as the capability of connecting the fitment to a pumping device. This permits the contents of the package to be dispensed in a controllable way. The particular coupling device described in U.S. Pat. No. 4,603,793 is mounted inside the pouch.
This arrangement avoids the disadvantages associated with externally mounted fitments. These include the difficulty of properly packing multiple pouch units, and the possibility that an external fitment will be damaged during handling/storage. If this happens, the food or other pouch contents can possibly leak out.
Packaging systems combining the Onpack(™) system with the fitment technology of U.S. Pat. No. 4,603,793 have proven effective in providing a pouch making system where the pouch, containing a food product, includes an internal fitment.
One of the requirements of using fitments of this general type is that they be accurately indexed and positioned to ensure that each fitment in a series of fitments is attached squarely to the film or pouch material at the appropriate location, for example by heat sealing the film to the fitment. If the fitments are not positioned accurately and consistently, they may not attach properly, and the resulting pouch or other container made from the film can possibly leak at the point where the fitment is joined to the film. In addition, inconsistent placement of the fitments with respect to the means for attaching (e.g. heat sealing means) and film can result in inconsistent attachment of a series of fitments on respective containers made from the film. Thus, for example, from pouch to pouch in a production run, the fitment on a given pouch may be located at a slightly different relative location on the pouch than another fitment on another successive pouch in the series.
U.S. Pat. No. 5,467,581 (Everette) offers an apparatus for accurately positioning fitments held in a queue for placement on pouch material. Two indexing devices shown in this reference include a multifingered wheel, and a pair of fingers with a counterweight. The former device has proven commercially useful, but still requires routine tension adjustments to insure proper performance.
The inventor has found an alternative to this technology is a device including a spring housing, a spring, and a fastener. This device offers high accuracy, and little or no tension adjustments over the useful life of the device.